Vast swaths of the Manhattan skyline went dark Monday night as ferocious winds and sea surges from the deadly storm Sandy battered the city.

There were more than 200,000 “customers” without power in Manhattan alone, Con Ed reported, with most of Manhattan below 39th Street dark. There was no timetable to getting the lights back on.

“This will be one for the record books,” John Miksad, Con Ed VP of electric operations, told reporters Monday night. “This will be the largest storm related outage in our history.”

There are 670,000 customers without power in all of New York City, with 230,000 in Manhattan, 73,000 on Staten Island, 140,000 in Brooklyn and Queens, 38,000 in Bronx and the rest in Westchester. By comparison, there were 200,000 customers down for Irene.

Power could be out for a week, he said.

But, the top of the Empire State Building remained lit and proved to be an eerie site amid the darkened buildings surrounding it.

Many took to the streets.

“It’s not too often you get see the city dark,” said Greg Pearl, 26, an accountant who was taking pictures on the East Side.

A group of people staying at the Affinia Garden, which lost power, were told to stay in their rooms, guests said.

So, they bolted en masse to check out the medieval-looking city.

“We are going to roam the city because I was never in a hurricane before,” said Susan Stubel, 42, visiting from Los Angeles.

There were reports of a deafening a “boom” in the East Village near the a power facility on the FDR facing the East River then the lights went out.

“Con Edison is reporting power outages to a large section of Manhattan stretching from East 39th Street to the lower tip of Manhattan,” Con Ed said in a statement about the 250,000 customers without power. “The outage was caused by flooding in company substations and engineers are working to correct the problem.”

A customer can be anyone from a single household to a large residential or commercial building.

It brought memories of the 2003 blackout with some restaurants continuing to serve meals and drinks by candlelight.

“I haven’t seen lower Manhattan shut down before. It’s kind of amusing,” said Jonathan Lee, 25, who walked across the Williamsburg Bridge to Manhattan with a buddy.

“It’s like an apocalypse, like a movie,” said his pal, Paul Parhar, 22.

A high-voltage feeder on 14th Street was also knocked out, Con Ed confirmed.

“When feeders go out they can be real loud — booming loud,” said a source with the utility.

The boom was heard throughout the city.

“It was scary! I was watching TV, looked outside the window and heard a big explosion and saw a big flash of white light like a firecracker,” said Maritza Mercado, 40, on East 6th Street.

A customer can be anyone from a single household to a large residential or commercial building.

The utility also reported that a storm surge downtown caused a substation equipment failure affecting more than 60,000 customers throughout Lower Manhattan and Greenwich Village.

“Carol, we lost power,” a panicked Con Ed worked said from its headquarters on 14th and Irving Place. Other staffers said they were navigating their own offices by flashlight.

Earlier in the evening Con Ed had announced it would preemptively shut down electricity in portions of the city in the bid to protect sensitive equipment.

Officials had warned New Yorkers to avoid elevators throughout the night before the city went dark. Some buildings even shut off their elevators preemptively.

But, it wasn’t bad for everyone.

“I think it’s fantastic. It actually feels like nighttime. For a city that doesn’t sleep, it’s finally sleeping,” said Rachel Lindover, 21.